The Simulation And Experimental Study On Broadband Designing Of The Clamped Beam Transducer

With the rapid development of micro-electromechanical systems and wireless network technology, microelectronics products have been widely used both in martial field and civil industries. These products need power to work, however, there are many obvious disadvantages of the chemical battery-based energy supply means, such as large bulk, limited lifespan, and environmental pollution, all which makes people began to develop environmental renewable energy. Featured by its advantages of non-pollution, simple installation, easy to achieve microminiaturize and integration, piezoelectric power generation device has currently become one of the research hotspots.Clamped beam piezoelectric transducer is the research object of this thesis. To improve the frequency response capability of energy harvester, making use of load mass to modulate and change the frequency in order to achieve the same frequency as exciting vibration source in external environment which can capture more energy. The simulation analysis showed that loading mass blocks can adjustment frequency, but it is not enough to achieve broadband. To further reduce the resonant frequency of the piezoelectric vibrator and narrow the natural frequency difference, another research designs both ends clamped Piezoelectric beam energy harvester with multi-sectionalized piezoelectric disk and multi-mass system. The simulation analysis reveals that this energy harvester can reduce the resonant frequency, narrow natural frequency difference, and achieve broadband to some extent, but its effects are not yet perfect enough. Based on the broadband performance of that structure, one research designs crossed beam piezoelectric energy harvester and makes adjustment to achieve better broadband effects. The finite element simulation analysis eventually testifies that this both ends clamped cross beam piezoelectric energy harvester can reduce the resonant frequency, narrow natural frequency difference and also achieve the effects of broadband.Boost-Buck piezoelectric energy storage was designed in this thesis. By applying NI Multisim10 circuit simulation software, here makes simulation analysis of the Boost-Buck energy storage circuit in turn and verifies the feasibility of energy storage circuit from simulation perspective.For the purpose of verifying the results of theoretical and finite element analysis results, the experimental system of clamped beam piezoelectric energy harvester is built up, uses PSV-400-m2 laser vibrometer to measure the vibration modes of each piezoelectric vibrator, and the measurement results are mainly consistent with finite element simulation results. The experiment also does energy harvesting research on various clamped beam piezoelectric energy harvesters, after comprehensive comparison of their of frequency regulation performance, broadband performance and energy harvesting performance, draws a conclusion that the energy density of crossed beam piezoelectric energy harvester is the highest in the 60-75Hz low-frequency. Verifying the Boost-Buck energy storage circuit performance finally, by changing the excitation frequency, switching frequency, matched load, the switch duty cycle to increase energy storage circuit energy capturing. Making a comparison between Basic storage and Boost-Buck circuit, results showed that Boost-Buck has superior performance in outputting stable, reducing the load impedance matching.